Bill Sifin has a gross estate with a current estimated value of $1.3 million. If he were to die immediately, his estate would have a severe liquidity shortage. The major assets in his estate are: half of the outstanding shares (owned solely by Bill) in a closely held business valued at $500,000; a residence (owned in tenancy by the entirety with his wife) with a total value of $400,000; and . a life insurance policy on his life (owned solely by Bill) with a face value of $300,000; Bill's mentally incapacitated son is the primary beneficiary. Which of the following actions would have the potential to improve the liquidity of Bill's estate? I. Bill should enter into a cross purchase buy-sell agreement with the owner or owners of the remaining shares in the closely held business funded with life insurance on each shareholder's life. II. Bill should gift his interest in the residence to his wife but retain a life estate. III. Bill should establish an irrevocable life insurance trust, and transfer ownership of the life insurance policy to the trustee of this trust. IV. Bill should place his shares in the closely held business into a revocable living trust that names himself, his wife, and his son as income beneficiaries so long as any of them shall live, with the remainder to a qualified charity. I and IV only II and III only I, III, and IV only I, II, III, and IV